87391 ÷ 7 = 12484 R3
Alright, let's work through the division of 87391 by 7 step by step.

Step 1:
7 goes into 8 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 7 from 8 to get 1.
Bring next digit (7) of the dividend behind the 1 and repeat the process: 17 / 7

Step 2:
7 goes into 17 2 times with a remainder of 3.
Write down 2 as next digit of of the result. 
Result so far: 12
Subtract 14 from 17 to get 3.
Bring next digit (3) of the dividend behind the 3 and repeat the process: 33 / 7

Step 3:
7 goes into 33 4 times with a remainder of 5.
Write down 4 as next digit of of the result. 
Result so far: 124
Subtract 28 from 33 to get 5.
Bring next digit (9) of the dividend behind the 5 and repeat the process: 59 / 7

Step 4:
7 goes into 59 8 times with a remainder of 3.
Write down 8 as next digit of of the result. 
Result so far: 1248
Subtract 56 from 59 to get 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 7

Step 5:
7 goes into 31 4 times with a remainder of 3.
Write down 4 as next digit of of the result. 
Result so far: 12484
Subtract 28 from 31 to get 3.

The final result is 12484 with a remainder of 3.